Pipe forming machine



- May 16, 1967 J. E. STALKER PIPE FORMING MACHINE 3 Sheets-Sheet 1 FiledNOV. 15 1963 c/ames BY Fly. 5

May 16, 1967 J. E. STALKER PIPE FORMING MACHINE 3 Sheets-Sheet 2INVENTOR.

Mffwwey y 1967 J. E. STALKER 3,319,445

PIPE FORMING MACHINE Filed Nov. 15, 1963 :5 sheets-sheet s Fly. 6

I NVEN TOR.

James 15 m/fie?" United States Patent 3,319,445 PIPE FORMING MACHINEJames E. Stalker, Richardson, Tex., assignor to Home Metal ProductsCompany, Plano, Tex., a corporation of Texas Filed Nov. 15, 1963, Ser.No. 323,965

6 Claims. (Cl. 7230) This invention relates to a pipe forming machine,and more specifically, to one having utility for forming sheet metalinto stove vent pipes and the like.

Stove vent pipes are well-known in the art and have been used for manyyears. Most commonly, sections are joined together by telescoping areduced end portion of one section onto the normal-sized end portion ofan adjoining section. The reduction in size of an end portion of asection is usually accomplished by fluting or otherwise corrugating theend portion. Stop means below the reduced end portion of a section tofirmly engage the normal-sized end of the adjoining section telescopingthereover are commonly provided by forming a rib joint below thecorrugated end portion.

Various methods of corrugating the end portion of a joint, providing astop rib below the corrugated section, and covering the sheet metal ofthe joint into the desired general cylindrical configuration have beenused; however, such methods commonly require a series of time-consuming,separately performed operations and awkward and/ or complex machinery.

It is an object of the present invention to provide a machine forperforming the corrugation and/or rib formations on the end of sheetmetal and, concurrently therewith, bending said metal into the desiredcurvature. Moreover, it is an object to provide such a machine that issimple, etficient, and economical. It is a further object to providesuch a machine that will perform the stated operations without deformingpre-formed edges on the sheet metal which are later interlocked to holdthe curved sheet metal into the desired rigid cylindrical position.

In accordance with this invention, a system for rolling a pipe sectionfrom a sheet having lea-d and trailing edges preformed to interlock, onewith the other, is provided which comprises an upper and a lower rollerwhich have an annular rib and groove portion adjacent to one end forworking a rib into a sheet; a forming roller on the back side of theupper and lower rollers for determining the curvature of the sheetforming roller, being spaced a different distance from the ends of theupper and the lower roller adjacent to the annular rib and grooveportion than from the other end of said rollers; means for elevating andlowering one of the rollers to permit the sheet to be inserted betweenthe rollers from the front; and a drive means operatively linked to theupper and lower rollers to drive the sheet past the forming roller.

An important feature includes adaption of the system for handling asheet with preformed lead and trailing edges so that said preformededges will not be deformed by said rollers during forming of the sheet.

A quite specific preferred embodiment of the instantinventioncontemplates a system for rolling a sheet having opposite lead andtrailing edges formed for interlocking, which comprises: a table havingstop means thereon against which the trailing edge abuts; a pair ofrollers positioned one above the other to define upper and lowerrollers,respectively, each of the rollers being generally tangent to the planeof the table at a distance from the stop means slightly less than thewidth of the sheet; means for elevating to an upper position andlowering to a forming position said upper roller to permit said sheet tobe inserted between said rollers, the upper roller and the lower rollerhaving an annular rib and groove portion adjacent to the one end forworking a rib into the sheet and having "ice male and female flutedportions extending between the rib and groove portion of the end of therollers for fluting the portion of the sheet beyond the rib; a formingroller on the side of the pair of rollers for determining the curvatureof the sheet, which forming roller is spaced a dilferent distance fromthe fluted end of the pair of rollers than from the other end of thepair of rollers; a drive means; a chain belt linked to the first andsecond rollers and to the drive means; a resiliently positioned followerfor engaging the chain link belt between the motor and the upper rollerto permit the upper roller to be elevated and lowered while maintainingregistration between the male and female fluted portions of the rollers;a timing rod mounted for translation adjacent the end of the tableopposite the belt; a timing wheel mounted for movement with the upperroller to engage the timing rod when the upper roller is in its lowerposition; and control means at a predetermined point in the path of thetiming rod for activating the elevating means for the upper roller apredetermined distance before the trailing edge of the sheet reaches therollers.

For a more complete understanding of the present invention and forfurther objects and advantages thereof, reference may now be had to thefollowing description taken in conjunction with the accompanyingdrawings in which:

FIGURE 1 is a rear perspective view of a preferred embodiment of theinstant invention;

FIGURE 2 is a side view of the apparatus of FIG- URE 1;

FIGURE 3 is a top view of the apparatus of FIG- URE 1;

FIGURE 4 is a partial side view showing the apparatus of FIGURE 1 withthe crown roller in forming position;

FIGURE 5 is a similar side view as FIGURE 4 except the crown roller isshown raised to its uppermost position;

FIGURE 6 illustrates a stove vent pipe, after assembly, which has beenformed by use of the instant invention;

FIGURE '7 is a partial view of certain details of the machine of FIGURE1, illustrating an adjustable sliding carriage in which the formingroller is journalized; I

FIGURE 8 is a simplified circuit diagram illustrating the electricalcircuitry for the machine of FIGURE 1;

FIGURE 9 is a schematic of the structure of FIGURE 10 in which the crownroller is shown separated from the base rollerand a work sheet is shownsupported there-be tween in position to be formed; and

- FIGURE 10 is a schematic view of a section taken along 10-10 of FIGURE3, showing a work sheet being formed between the rollers.

Referring now to FIGURE 1, a machine is therein illustrated which is apreferred embodiment of the present invention. It is shown as viewed inperspective from the rear, FRONT being indicated by an arrow inconnection with said figure. Accordingly, for purposes of locating partsand their relative location with respect to each other in thisspecification, it will be understood that reference to front refers tothe machine of FIGURE 1 as viewed from FRONT. Moreover, reference toright or to left refers to those directions as would appear when themachine is viewed from FRONT. The designation rear" will be consistentwith the foregoing.

A support means in indicated generally in FIGURE 1 by the referencenumeral 11. It comprises horizontal rectangular support deck 13,depending vertical legs 15, 17, 19 and 21, and co-planar leg braces 23,25, 27 and 29.

Right vertical standard 31 extends upwardly from the support deck 13 towhich it is firmly anchored. It is shaped generally as a rectangularblock. The right and left faces of the vertical standard 31 are inparallel vertical planes and are generally parallel to the edges ofsupport deck 13. Vertical standard 33 is, like vertical standard 31,generally rectangular in configuration. It also has right and leftparallel faces which are, in turn, parallel to the edges of support deck13. It is therefore seen that the Vertical standards 31 and 33 aredisposed with their opposite inner faces 32 and 34 in alignment.

Crown roller 35, base roller 37 and forming roller 39 are rotatablycarried by the vertical standards 31 and 33. The longitudinal axes ofall three of these rollers are generally parallel and are perpendicularto the inner faces 32 and 34 of the vertical standards. The crown roller35' and the base roller 37 are generally cylindrical and are ofsubstantially the'same diameter. Crown roller 35 is disposed above baseroller 37, the pair of rollers 35 and 37 thus defining an upper and alower roller, respectively. The forming roller 39 is positioned so thatits longitudinal axis lies behind the longitudinal axis of the crown andbase rollers. Forming roller 39 is tapered from left to right with itsgreatest diameter adjacent block 33 and its narrowest diameter adjacentblock 31. Its upper surface even at its narrowest diameter lies at ahigher elevation than the upper surface of the base roller 37.

A short'distance from the right end of crown roller 35, theflute-forming portion 41 is disposed on the surface of the roller. Itcomprises a plurality of alternate ridges and valleys running about thecircumference of the roller. These ridges and valleys are parallel tothe axis of the roller and are of the same length, with their left andright ends in alignment. An annular ridge 43 on crown roller 35 isdisposed a short distance to the left of the left end of theflute-forming portion 41. It runs circumferentially outwardly withrespect to the axis of the crown roller 35. Annular groove 44 in crownroller 35 lies just to the left of the annular ridge 43. Annular groove44 extends circumferentially inward with respect to the axis of crownroller 35.

The base roller 37 has a flute-forming portion 45 with alternate ridgesand valleys which mate with the valleys and ridges, respectively, of thecrown roller 35 when the two rollers are pushed together as illustratedin FIGURE 1 and in FIGURE 10.

' An annular groove 47 extends circumferentially inward in the curvedsurface of the base roller 37 a short distance from the left end of theflute-forming portion 45. Annular groove 47 is in vertical alignmentwith annular ridge 43 of the crown roller 35. Annular ridge 49 extendscircumferentially outward with respect to base roller 37. It is disposedimmediately to tthe left of annular groove 47 and is so located'that itis in vertical alignment with the annular groove 44 on crown roller 35.

The surface configurations of the annular ridges and grooves justdescribed and their relative orientation is such that they lie togetherin mating engagement when the crown roller is in contact with thesurface of the base roller.

The configuration used in the machine of FIGURE 1 for the mating offlute-forming portions and the mating of annular ridges and grooves justdescribed above can best be understood by reference to FIGURES l, 3, 9and and by reference to the upper portion of the vent pipe illustratedin FIGURE 6. It should be understood, however, that various otherconfigurations on the surfaces of the rollers 35 and 37 may besubstituted and it is not intended that this invention be limited by theconfigurations just described.

A slot 51 extends vertically downward in the vertical face 32 of block31. Crown bearing carriage block 53 rides in slot 51' with the sides ofthe carriage block in sliding engagement with the sides of the slot.Retainer strips 55 and 57 hold the crown bearing carriage within saidslot. Thus, only vertical motion of the block is permitted. Acylindrical bearing surface 59 is formed within the movable carriageblock 53, The journalized end of the crown roller 35 is carried withinthis bearing surface.

The end of the base roller 37 is journalized in a conventional recessedbearing surface formed in vertical standard 31.

An inclined rectangular slot 60 in face 32 of vertical standard 31extends downwardly and rearwardly from a central portion of verticalstandard 31. This rectangular slot is inclined with respect to thehorizontal to a noncritical angle, being about 20 in the embodiment ofFIGURE 1. Forming bearing block 61 is configured to slide within slot60. Retainer strips 63 and 65, fixed to face 32 of vertical standard 31by suitable means such as allen screws 66, overlie the edge of the slotto retain the forming bearing block 61 in slot 60 and confine said blockto movement along the inclined longitudinal axis of the slot.

A cylindrical bearing surface is formed within forming bearing block 61and it receives the journalized end of tapered forming roller 39.Adjustment screw 67 has its forward shank end 69 rotatably mountedwithin a bore running axially into bearing block 61. An annular groove71 runs about the cylindrical surface of screw 67 adjacent shank end 69.A pin 75 extends from the outer surface of the forming bearing block 61inwardly to ride within the annular depression 71 and confine screw 67with respect to block 61 so that only rotation is permitted with respectthereto. Screw 67 passes through and threadedly engages retainer 77,which is held in fixed position with respect to vertical standard 31 byfasteners such as allen screws 79. Thus screw 67 may be manipulated byrotating it to cause it to move either inwardly or outwardly withrespect to retainer 77. On such movement, block 61 is carried inward, oroutward, as the case may be, to position the bearing block 61 in thedesired location along slot 60.

The vertical support 33 supports the left end of the crown roller 35,the base roller 37 and the forming roller 39 in the same manner and byexactly the same parts and mechanisms .as have just beendescribed forthe support provided on the right end of said rollers. The onlydifference is, as will later be explained in more detail, drive meansare provided at the right end of the base and crown rollers but a timingwheel is provided at the left end of the crown roller.

The timing wheel 83 is a knurled, cylindrical member which is fixedlyjoined to the reduced cylindrical extension84 which runs axiallyoutwardy from the left side of the journalized end of crown roller 35.An elongated opening 85 in vertical standard 33 permits the cylindricalextension 84 to pass through the block and, moveover, provides roompermitting the crown roller 35 to be raised in the manner laterexplained herein. A timing rod 87 is carried on the left side of supportdeck 13, upon a plurality of rollers 89'and with its sides guided byspaced, parallel, vertical walls 91 and 93, which extend upward fromsupport deck 13. The rollers 89 are journalized at either end withinsuitable bearing-defining apertures running through the support walls 91and 93. As can be seen from reference to FIGURES l3, a cord 95 having aweight 97 supported from a free end is attached at the front end oftiming rod 87 and runs downwardly over an end sheave 99, which isjournalized at either end within bearing-forming supports within thesupport walls 91 and 93. For convenience, a second sheave (notillustrated, but its position discernible from the extending journalizedend 101 of its shaft which is visible in the lower left-hand frontportion of wall 93, as seen in FIG- URE l) is provided so that cord 95may pass over sheave 99 and then downwardly and inwardly over the secondsheave, thus locating the suspended end of cord 94 rearwardly from theextreme front portion of the apparatus of FIGURE 1. This displacement ismerely a matter of convenience to move the free end of cord 95 out ofthe way of an operator or passerby.

The relative location and configuration of the timing rod 87 and itssupport means described above, is such that when crown rolled 35 is inits lower position, illustrated in FIGURE 1, the knurled surface oftiming wheel 83 is in close frictional engagement with the surface oftiming rod 87. It will thus be appreciated that rotation of the crownroller, with the attendant rotation of knurled timing wheel 83, willdrive the metering rod along the rollers 89. Since the rotation of crownroller 35 is counterclockwise as viewed from the right side (the driveside) of the apparatus, it will be appreciated that the timing rod willbe moved rearward by such action.

A microswitch 103 is mounted at the rear of the parallel support wall93, along the outer side thereof. Its actuation arm 105 extendshorizontally across and behind the open end portion defined betweenwalls 91 and 93 so that it will be struck by the end of timing rod 87when timing rod 87 is moved rearwardly a sufficient distance.

Now turning to the drive mechanism, attention is first directed toFIGURE 4. An opening 111 passes through vertical standard 31. Thisopening is located with respect to the standard so that a cylindricalextension 113 from the journalized right end of crown roller 35 ispermitted to pass through said block 31. The opening 111 is configuredto provide a vertical slot permitting said extending end to moveupwardly and downwardly therein. The extending end 113 has keyed uponit, as by key 115, the crown roller drive gear 117.

The base roller 37 has an extending shaft portion 119 fixed to andrunning axially from its journalized right end. This portion passesthrough a suitable opening provided within vertical support block 31. Onthe outer side of the support block, i.e., the right side, base rollerdrive gear 121 is held in place on shaft 119 by means of key 123.

An idler gear 125 is supported by shaft 127, upon which it is held bykey 129. This shaft is journalized and conventionally supported withinvertical standard 31. It lies below base roller gear 121.

Motor 131 is supported by base 133, which is in turn mounted upon therear, right upper portion of support deck 13. Motor 131 carries asprocket 135 upon the end of its drive shaft. Sprocket 135 is alignedwith gears 117, 121 and 125. Drive chain 137 is in engagement with theteeth of sprocket 135, crown roller drive gear 117, base roller drivegear 121 and idler gear 125. The teeth of these various gears aresuitably engaged by drive links of drive chain 137, which consequentlydrives said gears.

Drive chain tension means are provided by a follower roller 141. Thisroller is rotatably mounted upon an extending shaft 143, which extendsfrom the end of arm 145. Arm 145 is pivotally mounted by pin 147, whichpin extends into the right vertical surface of vertical standard 31 nearits upper righthand portions. A spring 149 has its lower end 151supported by pin 152, which extends into the lower right-hand portionsof the right vertical face of vertical standard 31. The other end ofspring 149, i.e., generally its upper end, is connected to the lowerportion of arm 145. Spring 149 is in tension so that it pulls roller 143firmly downward against drive chain 137. This mechanism insures that thedrive chain 137 is maintained in tight driving position whether thecrown roller 35 is in the lower position, as shown in FIGURE 4, or theupper position, as shown in FIG- URE 5.

The work table 161 is mounted over the support deck 13 in front of thecrown roller 35 and base roller 37. It is supported by vertical supports163 and angular braces 165. Work table 161 is inclined downwardly to thefront a non-critical angle, for example, to degrees. Its upper,rectangular fiat surface is disposed so that a thin sheet of metal to beworked by the rollers will be substantially tangent to the top of thebase roller (and hence, the bottom of the crown roller, when the rollersare together) when the sheet metal rests upon the inclined table andextends over its rear portion adjacent the front of the rollers. TheWork table has a feed guide 169 mounted upon its upper surface near theright edge of the table and extending perpendicular to the rollers. Feedguide 169 provides a means to insure that a rectangular sheet is fedstraight into the rollers.

Initial positioning guides 171 are provided adjacent the front portionof the work table. They are small rectangular pieces having parallelaligned edges facing the crown and base rollers 35 and 37, respectively.Initial positioning guides 171 insure that the work is properlyinitially inserted a proper distance with respect to the rollers. Aswill later be more readily appreciated, the guides 171 lie in front ofsaid rollers a somewhat shorter distance than the width of the sheet tobe formed.

A conventional double-acting cylinder 181 is secured upon the upperportion of vertical support 31. Conventional piston rod 185 extendsdownwardly from the cylinder into the generally rectangular openingformed in the upper portion of vertical support block 31 and by itslower portion 187 threadedly engages crown bearing carriage block 53.Lock nut 189 is provided on the lower portion 187 of the piston rod toadjustably secure the piston rod with respect to crown bearing block 53.

Cylinder 191 is identical to cylinder 181. It rests upon the upperportion of left vertical standard 33. Analogous to cylinder 181,cylinder 191 has a downwardly extending piston rod connected to a crownbearing carrier block sliding within a vertical slot provided invertical standard 33.

A horizontal shelf 201 is supported in between braces 25 and 29.Solenoid valve 203 is held in position on the upper central portion ofshelf 201, as by bolts 205. This solenoid valve is a conventional 4-wayvalve type. The particular one illustrated is solenoid-operated withspring return means. It has air inlet nipple 207 extending into itsvalve body. Air supply line 209 is connected to 207. Conventionalexhaust ports 211 and 212 are provided. Ts 213 and 215 extend upwardlyfrom two air ports provided in the valve. The solenoid 217 adjoins theright side of the 4-way valve. A solenoid connection conduit 219 leadsfrom solenoid 217 to the conduit boxes 221.

Upper cylinder air supply lines 223 and 225 join the upper portions ofcylinders 181 and 191, respectively, with the air supply through T 213.Cylinder air supply lines 227 and 229 extend from their connection witheither side of the T 215 to connect with the upper portions of thedouble-acting cylinders 181 and 191, respectively.

Hand actuated motor switch 231 is mounted on the right front of leg 15in a convenient position. It is connected to the conduit box 221 byelectrical cable 233. In turn, electrical cable 235 leads to the motorfrom conduit box 221.

Microswitch 103 is electrically connected through cable 237 to theconduit boxes 221. Y

A foot operated switch 241 lies on the floor in front of the supportmeans 11 of FIGURE 1. This switch is closed when its treadle isdepressed by the foot of an operator. Switch 241 is electricallyconnected by cable 243 to conduit box 221.

The wiring of the various electrical parts and arrangement of wireswithin conduit "box 221 can best be understood by reference to thesimplified'circuitdiagram of FIGURE 8. Therein, power leads 251 and 252(leads of power cable 245) have connected in parallel across them themotor 131 and the solenoid 217. Referring to the motor circuit, themotor switch 231, illustrated in open position, is closed to actuate themotor. Referring to the solenoid circuit, the foot switch 241, normallyopen, and the microswitch 103, normally closed, are in line With thesolenoid 217. Thus, while the foot switch is depressed, the opening ofmicroswitch 103 breaks the circuit to the solenoid. The significance ofthe operation of the solenoid circuit will be explained hereinafter inconnection with an explanation of the operation of the machine.

Now turning to machine operation in general, the crown roller is raisedabove the base roller, thus permitting the sheet to be worked to beinserted with its leading edges extending a short distance rearward ofthe base and crown rollers. Thereafter, the crown roller is forceddownward against the sheet to be worked to press it between the crownand base rollers and drive the sheet therebetween while theflute-forming portions and grooves and ridges on the rollers corrugateand form -a rib and adjacent depression in the sheet. The sheet isconcurrently bent by the forming roller to the desired degree ofcurvature. A short distance prior to passage of the trailing edge of thesheet between the crown and base rollers, the rollers are effectivelyseparated by the raising of the crown roller. This permits the Work tobe removed without the damage which otherwise would occur to the lip onthe trailing edge of the work sheet. Thereafter, the cycle describedabove may be repeated to form additional work sheets into the desiredconfiguration.

Operation will now be explained in more detail. The solenoid valve 203in its non-energized position conducts air from air line 209 to theunderseide of the piston working within the double-acting cylinders 181and 191 through lines 227 and 229, respectively. The top portion of thecylinders is vented through exhaust port 211 via lines 223 and 225.Accordingly, the piston is held in the up position by air pressure.Piston rod 187, as well as the like piston rod extending from cylinder191, is thus maintained in the raised position as shown in FIG- URE 5.This positions crown bearing block 53, and the like block slidingvertically in vertical standard 33, in their highest elevation (seeFIGURE In this position, crown roller 35 rests well above the uppersurface of base roller 37 and work can easily 'be inserted therebetween(see the position of FIGURE 9). Note that the initial positioning guides171 are located on inclined table 161 so that the work sheet 261 restswith its trailing edge abutting the guide 171 and its leading edgeextending behind the point of ultimate tangency of the crown and baserollers. The locking lip on the leading edge of the work sheet is thuscleared for the crown roller to be lowered. Note the leading edgeoverlies the upper surface portions of the forming roller 39 when in theinitial position.

After the work is positioned as just described and as illustrated inFIGURE 9, the treadle on the foot operated switch 241 is depressed toclose the switch contacts. Since the microswitch 103 is normally closed,the solenoid circuit is consequently completed (see FIGURE 8) and thevalve element within solenoid valve 203 retracted by the solenoid 217 toan energized position connecting the various air ports so that the upperportions of cyinders 181 and 191 are pressurized with air from airsupply line 209 via lines 223 and 225. The lower portions of thecylinders 181 and 191 are vented to the atmosphere via lines 227 and229. In this position, the pistons within cylinders 181 and 191 areforced to the down position (see piston rod 185 in FIGURE 4). Theattached crown bearing blocks accordingly carry the crown roller 35down. The crown roller 35 is thus moved downwardly against the worksheet 261. The flute-forming portions and ridges and grooves of thecrown and base rollers force the Work to conform to the desired flutedand ribbed and grooved configuration as it is drawn between the rollers(see FIGURE 10). The work sheet passes from the crown and base rollersup over the forming roller 39 to bend the sheet to the desired degree ofcurvature. At all times during the operation the pressure in the upperportions of the cylinders 181 and 191 is maintained so that asubstantial force is exerted upon the work sheet during forming.

Timing rod 87 is in its forwardmost position, where it is maintained byweighted cord 95, at the instant that the crown roller is lowered toform a work sheet. When the crown roller lowers, the knurled timingwheel 83 engages the timing rod 87 and frictionally drives it forwardwhile the crown roller rotates. At the proper predetermined interval(determined by the appropriate length of timing rod 87, proper sizing ofthe knurled wheel 83, and/ or proper positioning of microswitch arm 105)the rear end of the timing rod 87 strikes the microswitch arm 105 andopens the microswitch. This opens the circuit to the solenoid and aspring return within the 4-way solenoid valve 203 forces the valveelement of the solenoid to the disengaged position. In this position,air is again forced in under the pistons in cylinders 181 and 191 andexhausted above them. Thus crown roller is raised to its upper position.The foot operated switch 241 is released by the operator as the crownroller rises and the formed work sheet is removed.

Note that after the crown roller is raised on actuation of microswitch103 and the foot operated switch returns to the open position, the pullcord retracts the timing rod 87 to pull it along its path over rollers89 to its forwardmost position. It will thus be appreciated that themachine is then ready in all particulars for another cycle. Another worksheet can then be inserted, if desired, and the treadle of the footoperated switch depressed to drive the rollers together and againcommence the cycle.

Throughout the operation of the machine, whether the crown roller is inthe upper or lower position, the follower roller 141 bears down firmlyagainst drive chain 137 to keep it taut in driving engagement with gears117 and 121.

The relative location of the forming roller 39 is determinative of thecurvature of the work passing through the machine. This curvature of thework passing through the machine. This curvature is adjustable byadjustment of the location of the forming roller 39 by suitablemanipulation of the adjustable screw 67, as previously described herein.

The embodiment illustrated is suitable to work sheets of variousthickness depending upon its scale and upon the force of the crownroller.

It should be noted that the tapering of the forming roller provides asubstantially greater spacing between the right end af the rollers,where the fiuting and ridge forming operation is accomplished, and onthe other end. This provides needed clearance so that the formedportions of the sheet being worked may properly clear the machine. Inaddition, .it is sometimes desirable to have a machined groove providedon the forming roller to assure clearance with rib forming structure onthe crown and base rollers. Groove 262 in forming roller 39 (FIG- URE 1and FIGURE 3) is an example of this experiency.

Various auxiliary devices are found useful in conjunction with theembodiment illustrated. For example, in FIGURE 1, a conventional counter263 is provided to count the number of sheets worked by the machine.This is accomplished by contact of the front of the timing rod 87 with asmall counter actuator arm, which causes the counter to register eachtime the metering rod strikes the arm.

Having described the invention in connection with certain specificembodiments thereof, it is to be understood that further modificationsmay now suggest themselves to those skilled in the art and it isintended to cover such modifications as fall within the scope of theappended claims.

What I claim is:

1. In a system for rolling a pipe section from a sheet having lead andtrailing edges performed to interlock one with the other, thecombination which comprises:

(a) an upper and a lower roller, said upper roller and said lower rollerhaving an annular rib and groove portion adjacent to one end for workinga rib into said sheet,

(b) a forming roller on the back side of the upper and lower rollers fordetermining the curvature of said 9 said sheet, said forming rollerbeing spaced a diflerent distance from the ends of said rollers adjacentto said annular rib and groove portion than from the other end of saidrollers,

() means for elevating and lowering one of said rollers to permit saidsheet to be inserted between said rollers from the front, and

(d) a drive means operatively linked to said upper and lower rollers todrive said sheet past said forming roller.

2. In a system for rolling a pipe section from a sheet having lead andtrailing edges preformed to interlock one with the other, thecombination which comprises:

(a) a pair of drive rollers positioned one above the other to define atop and a bottom roller,

(b) means for elevating and lowering the top roller to permit said sheetto be inserted between said rollers, said top roller and said bottomroller having mating annular rib and groove portions adjacent to one endof said pair for working a rib into said sheet and having mating flutedportions extending between said rib and said end of said pair forcorrugating the portion of said sheet beyond said rib, and

(c) a forming roller behind said pair of rollers for determining thecurvature of said sheet, said forming roller being spaced farther fromthe fluted ends of said pair than from the other end thereof.

3. A system for rolling a sheet having opposite lead and trailing edgesformed for interlocking, which comprises:

(a) a table having stop means thereon against which one of said edgesabuts,

(b) a pair of rollers positioned one above the other to define an upperroller and a lower roller respectively, said rollers being generallytangent to the plane of said table at a distance from said stop meansslightly less than the width of said sheet,

(c) means for elevating to an upper position and lower ing to a formingposition said upper roller to permit said sheet to be inserted betweensaid rollers, said upper roller and said lower roller having an annularrib and groove portion adjacent to one end for working a rib into saidsheet and having male and female fluted portions extending between saidrib and groove portion and said end of said rollers for fluting theportion of said sheet beyond said rib,

(d) a forming roller on the side of said pair of rollers for determiningthe curvature of said sheet, said forming roller being spaced adiiferent distance from the fluted ends of said rollers than from theother end of said rollers,

(e) a drive means, i

(f) a chain belt linked to said upper roller and said lower roller andto said drive means,

(g) a resiliently positioned follower for engaging said chain link beltbetween said drive means and the upper roller to permit said upperroller to be elevated and lowered while maintaining registration betweensaid male and female fluted portions,

(h) a timing rod mounted for translation adjacent the end of said tableopposite said belt,

(i) a timing wheel mounted for movement with said upper roller to engagesaid timing rod when said upper roller is in its lower position, and

(j) control means at a predetermined point in the path of said timingrod for activating said means for elevating said upper roller to anupper position a predetermined distance before the trailing edge of saidsheet reaches said rollers.

4. A system for rolling a sheet having opposite lead and trailing edges,which comprises:

(a)'a pair of elongated rollers having mating male and female formingportions thereon adjacent one end and central roller portions,

(b) drive means for said rollers,

(c) an elongated forming roller behind said pair of rollers, saidforming roller being positioned farther from said pair of rollersadjacent said one end than from said central roller portion,

(d) means for moving said rollers apart and together,

(e) first control means to actuate said means for moving said rollerstogether, and

(f) second control means responsive to a predetermined position of asheet in between said rollers to actuate said means for moving saidrollers apart. 5. A pipe forming machine for rolling and working pipefrom a metal sheet having a lead and a trailing edge comprising:

(a) a crown roller having flute-forming portions and an annular ribadjacent one end, said roller being carried by vertically movablebearing means at either end thereof,

(b) a base roller lying below said crown roller and having flute-formingportions which are adapted to mate with the flute-forming portions onsaid crown roller and having an annular groove which is adapted to matewith said annular rib on said crown roller,

(c) a forming roller disposed behind said crown roller and base roller,said forming roller being spaced farther from said crown roller and baseroller in the proximity of said flute-forming portions and said annularrib and said annular groove than for the balance of the length of saidcrown roller and base roller,

((1) means mounting said vertically movable bearing means for verticalmovement,

(e) force application means for moving said vertically movable bearingmeans upward from a normal position in which said vertically movablebearing means rotatably hold said crown roller close to said base rollerto a raised position in which said crown roller is separated from saidbase roller to permit the insertion of work between said crown rollerand base roller,

(f) drive means for said crown roller and base roller,

and

(g) means for actuating said force application means (g) Means foractuating said force application means to raise said crown roller to theupper position at a predetermined distance before the trailing edge of asheet being formed by said machine passes between said crown roller andbase roller.

6. The pipe rolling machine of claim 5 in which said means for actuatingsaid force application means comprises:

(a) a frictional wheel extending from said crown roller,

(b) a timing rod engaged by said frictional wheel when the crown rolleris in the lower position, and

(c) an actuator located at a predetermined position in the path of saidtiming rod.

References Cited by the Examiner UNITED STATES PATENTS 49,045 7/ 1865Valentine et a1 72-171 543,971 8/1895 Stoll 7230 947,291 1/ 1910Berghausen 72--168 FOREIGN PATENTS 960,708 6/ 1964 Great Britain.

CHARLES W. LANHAM, Primary Examiner.

L. A. LARSON, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,319,445 May 16, 1967 James E. Stalker It is certified that errorappears in the above identified patent and that said Letters Patent arehereby corrected as shown below:

Column 3, line 49, for "tthe" read the column 4, line 48, for "outwardy"read outwardly line 64, before bearing" insert suitable column 5, line3, for "rolled" read roller column 7, line 24, for "underseide" read Hunderside line 54, for "cyinders" read cylinders column 8, lines 33 and34, strike out "This curvature of the work passing through themachine."; line 51, for "experiency" read expediency line 68, for"performed" read preformed line 75, strike out "said"; column 10, line46,

strike out "(g) Means for actuating said force application means".

Signed and sealed this 22nd day of July 1969. (SEAL) Attest: Edward M.Fletcher, 11. JR.

Attesting Officer Commissioner of Patents

1. IN A SYSTEM FOR ROLLING A PIPE SECTION FROM A SHEET HAVING LEAD ANDTRAILING EDGES PERFORMED TO INTERLOCK ONE WITH THE OTHER, THECOMBINATION WHICH COMPRISES: (A) AN UPPER AND A LOWER ROLLER, SAID UPPERROLLER AND SAID LOWER ROLLER HAVING AN ANNULAR RIB AND GROOVE PORTIONADJACENT TO ONE END FOR WORKING A RIB INTO SAID SHEET, (B) A FORMINGROLLER ON THE BACK SIDE OF THE UPPER AND LOWER ROLLERS FOR DETERMININGTHE CURVATURE OF SAID SAID SHEET, SAID FORMING ROLLER BEING SPACED ADIFFERENT DISTANCE FROM THE ENDS OF SAID ROLLERS ADJACENT TO SAIDANNULAR RIB AND GROOVE PORTION THAN FROM THE OTHER END OF SAID ROLLERS,(C) MEANS FOR ELEVATING AND LOWERING ONE OF SAID ROLLERS TO PERMIT SAIDSHEET TO BE INSERTED BETWEEN SAID ROLLERS FROM THE FRONT, AND (D) ADRIVE MEANS OPERATIVELY LINKED TO SAID UPPER AND LOWER ROLLERS TO DRIVESAID SHEET PAST SAID FORMING ROLLER.